This invention relates generally to the art of radio broadcasting audio signals, and more specifically, to a system for transmitting and receiving pre-recorded audio messages over predetermined subcarrier channels or sidebands for reception by selective receivers.
The use of subcarrier channels or selective sidebands for FM transmission to selective receiving stations has been in widespread use for sometime. Such systems have become popular for example, in broadcasting continuous music programs to subscribers of the system and who are provided with necessary receivers or adaptors so that the subcarrier channels or sideband frequencies may be received by the subscriber but not by other commercially available FM receivers. The use of such systems has become popular for the transmission of continuous music programs to such subscribers as restaurants, retail stores, supermarkets, etc. On such commercially available system which offers its service to subscribers known as Muzac.TM. offers the continuous music format to its subscribers.
Another such service known as Supermarket Network.TM. operated by Audio Media Corporation of Valley Stream, New York, provides the additional feature of broadcasting selected advertising messages at predetermined intervals to each of the subscribers. The desired advertising message can be pre-recorded on tape or audio disc and selectivey broadcast over the channels subscribed for.
In-store audio message advertising systems can be implemented by placing individual tape recording and public address systems connected to the tape recorders directly within each store for broadcasting the particular advertising messages. Such systems, however, require that each retail outlet (more typically supermarkets) be provided with the complete advertising programs on pre-recorded tapes or discs so that mass duplication of such tapes or discs would be required if it is desired that the advertising messages be broadcast in numerous locations. The use of a central broadcast station constitutes an advance in that the same advertising messages can be broadcast simultaneously to numerous locations over selected channels to subscribers of the service who are provided with specially equipped receivers. Although such systems have met with commercial success, the number of locations or consumers who can be reached by a broadcast from a single station is limited by the range of the local broadcast station. Accordingly, if it were to be desired to broadcast a particular advertising message to numerous supermarket receivers located either nationally or regionally throughout the United States, it would be necessary to duplicate the pre-recorded advertising messages and provide each local transmission station with the same message for individual transmission to the local receivers being serviced by that particular FM transmitter.
Coast-to-coast transmission of audio signals over existing private lines, through relay broadcast or cable transmission, are capable of delivering the desired advertising messages originating from a central taperecorded carrier. However, such systems are relatively expensive and require multiple line-of-sight repeater stations and switching centers. Such networks create potential trouble spots along a given transmission line and a possibility of transmission breakdown at a number of intermediate stations. Additionally, while such existing networks are capable of transmitting the desired messages over long distances, the quality of the transmitted signal is subject to localized transmission conditions.
It is accordingly one object of the present invention to provide a system by which selected advertising messages can be centrally recorded, centrally played-back and yet broadcast to a multitude of receivers regardless of location throughout the entire continental United States without the necessity of installing individual tape-playing and transmitting equipment at local broadcast stations.
A further and more specific object of the present invention is to provide a message broadcast system in which the pre-recorded messages can be broadcast to a multitude of receivers simultaneously over long range distances through the use of existing earth orbiting, spin stabilized, synchronous, geostationary, space satelite network systems.
Yet, another object of the present invention is to provide a system for broadcasting desired advertising messages over selective subcarrier channels to subscriber receivers simultaneously with a muted musical background.
Another general object of the present invention is to provide a system for transmitting audio messages to subscriber receivers by means which avoid the disadvantages of conventional land-line services through the use of existing earth orbiting satelite networks. Through the use of satelite transmission, the cost and quality of the signal transmitted is substantially unaffected by the distances of transmission involved and employ a minimum of relay transmission stations.
Yet, another object of the present invention is to provide an efficient and reliable means for carrying the desired message signals to and from the transmission stations for relaying signals to the earth orbiting satelite through the use of existing microwave channels.
Still, a further object of the present invention is to provide a system by which the selected advertising messages can be transmitted to regional receiver locations through the use of microwave channels so that while the same message is being broadcast via satelite between coast-to-coast locations, the message can be simultaneously broadcast via microwave channels to closer locations.
The above objects, features and advantages, along with other objects, features and advantages of the invention will become more apparent from the detailed description of the invention in connection with the accompanying drawings to be described more fully hereinafter.